Ingress Protection Rating (also International Protection Rating) rates the degrees of protection against the penetration of objects into electrical equipment. The IP rating is a helpful guide to consider when selecting a lighting fixture that will be situated in damp conditions such as bathrooms or outdoors. Most outdoor lights will have an associated IP rating, so it comes down to selecting the correct lighting fixture for your desired location.
The IP rating is represented with two numbers indicating the level of protection against solids and liquids. The first number defines the level of protection against the penetration of Solid Objects into the housing of the product. The second number defines the level of protection against the penetration of Liquids in the housing of the product.